sodium

Sodium

Name:Sodium (natrium, the German name)

Symbol:Na

Atomic Number:11

Atomic Mass:22.98976928

Density:23.78 g/cm^3^

Melting Point: 97.72 �C

Boiling Point: 883 �C

Electronic Configuration: 2.8.2

Group Number:1

Group Name:Alkali Metals

Standard state:solid at room temperature

Color:silvery-white

Classification:Metallic

Soap is generally a sodium salt of fatty acids. The importance of

common salt to animal nutrition has been recognized since prehistoric

times. The most common compound is sodium chloride.

Sodium salts impart a characteristic orange/yellow color to flames.

The picture above shows the color arising from adding common salt

(NaCl) to a burning mixture of potassium chlorate and sucrose.

Sodium is a Group 1 element. Group 1 elements are often referred to as

the "alkali metals". The chemistry of sodium is dominated by the +1

ion Na^+.

Isolation

Sodium would not normally be made in the laboratory as it is so

readily available commercially. All syntheses require an electrolytic

step as it is so difficult to add an electron to the poorly

electronegative sodium ion Na^+.

Sodium is present as salt (sodium chloride, NaCl) in huge quantities

in underground deposits (salt mines) and seawater and other natural

waters. It is easily recovered as a solid by drying.

Sodium chloride has a high melting point (> 800�C) meaning that it

sould be expensive to melt it in order to carry out the electrolysis.

However a mixture of NaCl (40%) and calcium chloride, CaCl[2] (60%)

melts at about 580�C and so much less energy and so expense is

required for the electrolysis.

cathode: Na^+(l) + e^- -> Na (l)

anode: Cl^-(l) -> ^1/[2]Cl[2] (g) + e^-

The electrolysis is carried out as a melt in a "Downs cell". In